Marine propulsion system with fuel line cooler

ABSTRACT

A fuel line cooler (34) is provided for a marine propulsion system (2) having a water cooled internal combustion engine (4) in a heat retentive compartment (5). The fuel line cooler (34) has an inlet (36) in communication with the source (14, 12) of cooling water for the engine (4), and has an outlet (38) for discharging water. The fuel line cooler (34) is cooled by sea water during running of the engine (4). Upon turn off of the engine (4), the cooled water in the fuel line cooler (34) is in heat transfer relation with the fuel and prevents vaporization and or spewing of the fuel.

BACKGROUND AND SUMMARY

The invention arose during development efforts relating to a marinepropulsion system having an engine in a closed or heat-retentivecompartment causing problems of vapor lock, and or spewing.

After the engine is turned off, the temperature in the closedheat-retentive compartment in a marine propulsion system continues torise. The fuel line and fuel pump are no longer cooled by the flow ofincoming fuel from the cooler fuel tank. The stagnant fuel sitting inthe fuel line and the fuel pump will begin to vaporize and or boil asthe fuel line and fuel pump continue to heat up.

It is known in the prior art to provide insulation around the fuel linesto isolate the fuel from the heat.

The present invention addresses and solves the above noted fuelvaporization problem by providing a thermally inertial mass which isactively cooled during running of the engine, and which preventsvaporization of the fuel after the engine is turned off. A fuel linecooler in the compartment is in heat transfer relation with the fuelline and has an inlet communicating with the source of cooling water forthe engine and has an outlet for discharging water. During running ofthe engine, water is circulated through the fuel line cooler. After theengine is turned off, the cooled water in the fuel line cooler providesthe noted thermally inertial mass to prevent vaporization of the fuel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a marine propulsion system with a fuel line cooler inaccordance with the invention.

FIG. 2 is an exploded isometric view of a portion of the system in FIG.1.

FIG. 3 is an isometric view of a portion of the fuel line cooler ofFIGS. 1 and 2.

FIG. 4 is a sectional view taken along line 4--4 of FIG. 3.

FIG. 5 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 6 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 7 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 8 is a sectional view taken along line 8--8 of FIG. 7.

FIG. 9 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 10 is a sectional view taken along line 10--10 of FIG. 9.

FIG. 11 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 12 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 13 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 14 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 15 is a sectional view taken along line 15--15 of FIG. 14.

FIG. 16 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 17 shows a further embodiment of a fuel line cooler in accordancewith the invention.

FIG. 18 is a sectional view like FIG. 4 and shows a further clampingarrangement.

FIG. 19 is a top view of the structure in FIG. 18.

FIG. 20 is an end view of the clamp in FIG. 18.

DETAILED DESCRIPTION

FIG. 1 shows a marine propulsion system 2 including an inboard engine 4in a closed heat-retentive compartment 5 and drivingly connected throughthe boat transom 6 to stern drive 8 for rotating propeller shaft 10. Thestern drive has a water outlet 12 for supplying cooling water to theengine. This cooling water is supplied by a sea water pickup pump 14,FIG. 2, for which further references may be had from Kiekhaefer U.S.Pat. No. 2,466,440 and Bloemers et al U.S. Pat. No. 4,392,779,incorporated herein by reference. A portion of FIG. 2 is taken from theMercruiser "Service Training Notebook" 90-90593 4-985, page 127, andshows a Mercury Marine MCM 120 engine with standard cooling. In suchstandard cooling embodiment, sea water from pickup pump 14 is suppliedthrough water line 12 to thermostat housing 16. When the engine is cold,the water from input line 12 first fills the engine and then is divertedby thermostat 16 to output line 18 which in turns supplies the water toexhaust manifold 20 and exhaust elbow 22. The exhaust elbow dischargesthe water with the products of combustion, for which further referencemay be had from Sarra U.S. Pat. No. 3,541,786, incorporated herein byreference. When the engine warms sufficiently, cooling water from inlet12 flows through thermostat 16 to passage 24 and is then circulated byengine circulating pump 26 through engine 4. Fuel pump 28 pumps fuelfrom a remote tank (not shown) and delivers the fuel through fuel line30 to fuel distribution means such as carburetor 32 for supplying fuelfor combustion.

In accordance with the invention, a fuel line cooler 34 has an inlet 36communicating with the source of cooling water for the engine, and hasan outlet 38 for discharging water. Inlet 36 is a water hose which maybe connected to line 12 by means of a T-fitting 39, FIG. 1, or tothermostat housing 16 upstream of the thermostat valve therein, FIG. 2,or various other connections for providing the cooling water. Though astandard cooling system is shown providing sea water as the coolingwater for the engine, the invention is of course applicable to systemswhere sea water is provided to a heat exchanger through which enginecooling water is circulated, commonly known as a closed cooling system.Outlet 38 is connected to exhaust manifold 20, though may be connectedto water passage 18, or to other outlets for discharging the water, ordirectly discharged overboard. Sea water pickup pump 14 supplies coolingsea water for both engine 4 and fuel line cooler 34. Fuel line cooler 34is between fuel pump 28 and carburetor 32 and cools the fuel linedownstream of fuel pump 28. Alternatively or additionally, cooling waterfrom inlet 36 may be provided to a water cooled fuel pump, for exampleMickle et al U.S. Pat. No. 3,835,822 and Alden U.S. Pat. No. 2,791,186,incorporated herein by reference.

Fuel line cooler 34 includes a water hose 40, FIGS. 2-4, concentric tofuel line 30 and defining an annular space 42 through which coolingwater flows in direct contact with the exterior surface of fuel line 30.The inlet includes water hose 36 connected to fitting 44. A compressionring 46 around fuel line 30 is compressed in sealing relation by acompression nut 48 around fuel line 30 and tightened to threaded fitting44 to which water hose 40 is clamped. Fitting 44 has an inlet port 52which is exteriorly barbed at 54 to receive and retain water hose 36communicating therethrough with annular space 42. Fitting 44 has anexterior hex configuration for tightening to hex nut 48. Fitting 44 alsohas a slightly reduced outside diameter portion 56 for receiving waterhose 40 and clamped by a hose clamp or by a plastic clip 58 as providedby a press-on clamp with mating serrated barbed fingers 60 and 62 andretained by outer finger 64, such as an SNP 24 clamp. The outlet at 38is comparable. Water hose 40 is a bellows-type hose axially expandablealong the direction of fuel line 30 and enabling selective placement ofinlet 36 and outlet 38 along the fuel line to selectively control thelength of the fuel line to be cooled. Concentric axially expandablebellows hose 40 selectively enables cooling of substantially the entirefuel line between fuel pump 28 and carburetor 32, or cooling of only aportion of such fuel line by spacing one or both of the inlet 36 andoutlet 38 from its respective end of the fuel line between fuel pump 28and carburetor 32.

FIG. 5 shows an alternate embodiment and uses like reference numeralsfrom the above figures where appropriate to facilitate clarity. The fuelline cooler is provided by a water hose 40a wound in a helical coilaround fuel line 30a such that cooling water flowing through helicalcoil hose 40a cools the hose which in turn cools the fuel line.

FIG. 6 shows another embodiment and like reference numerals are usedfrom the above figures where appropriate to facilitate clarity. The fuelline cooler includes a water hose 40b, The fuel line 30b is wound in ahelical coil around water hose 40b.

FIGS. 7 and 8 show another embodiment and like references numerals areused from the above figures where appropriate to facilitate clarity. Thefuel line cooler includes a clamp 70 clamping water hose 40c into heattransfer relation with fuel line 30c. Water hose 40c is clamped intodirect heat transfer contact with fuel line 30c, FIG. 8, in parallelside-by-side relation. Clamp 70 has a central elongated shank 72extending axially along and engaging a portion of fuel line 30c andhaving an axial locating groove 74 for receiving the fuel line. A firstpair of opposing jaws 76 and 78 extend oppositely radially from centralshank 72 and partially around water hose 40c and terminate at respectivejaw ends 80 and 82. A second pair of jaws 84 and 86 are axially spacedfrom the first pair of jaws 76 and 78 and extend oppositely radiallyfrom central shank 72 and partially around water hose 40c. A third pairof jaws 88 and 90 are axially spaced from the second pair 84 and 86 andextend oppositely radially from central shank 72 and partially aroundwater hose 40c. A hose clamp 92 is placed around water hose 40c andguided by outer shoulders 76a, 76b and 78a, 78b on jaws 76 and 78 andtightened by hose clamp screw 94. Hose clamps 96 and 98 are likewiseprovided around their respective jaws for clamping to the water hose.

FIGS. 9 and 10 show another embodiment and use like reference numeralsfrom the above figures where appropriate to facilitate clarity. A rubberhose 100 has a fuel passage 102 therethrough for either receiving fueldirectly or receiving fuel line 30d. Rubber hose 100 is affixed to waterhose 40d, for example by vulcanizing. Alternatively, hose 100 and hose40d are integrally molded rubber having a figure eight shapedconfiguration in cross section, FIG. 10, with one of the loops of thefigure eight defining a water passage 104, and the other of the loops ofthe figure eight defining a fuel passage 102. Only a portion of waterhose 40d need extend contiguously along integral with or affixed to hose100, and other sections of the water hose may continue to respectiveinlet and outlet ports, for example as shown at water hose sections 106and 108.

FIG. 11 shows another embodiment and uses like reference numerals fromthe above figures where appropriate to facilitate clarity. A portion ofthe flywheel housing 110 for a stern drive on the inboard side of thetransom is shown. This housing section is formed with an extraupstanding base member portion 112 having a groove 114 therein receivingfuel line 30e and water hose 40e. A cap member 116 is mounted by bolts118 and 120 to base member 112 and holds water hose 40e and fuel line30e in heat transfer relation. Groove 114 is generally V-shaped, andfuel line 30e is in the bottom of the groove and water hose 40e directlycontacts fuel line 30e. The profile of water hose 40e is higher than theouter edge of the V-shaped groove 114, and cap member 116 is curvedaround over the top of water hose 40e.

FIG. 12 shows another embodiment and uses like reference numerals fromthe above figures where appropriate to facilitate clarity. Base member112a is similar to base member 112 and has a first groove 122 providinga fuel passage 124 for directly receiving fuel or for receiving fuelline 30f, and has a second groove 124 providing a water passage directlyreceiving water or receiving water hose 40f. Cap member 116a is mountedto base member 112a by bolts 118a and 120a and closes fuel passage 122and retains fuel line 30f therein, if present, and closes water passage124 and retains water hose 40f therein if present. Fuel line 30f isspaced and separate from water hose 40f by the material of base member112a. Heat transfers between the fuel passage and the water passagethrough the base member material.

FIG. 13 shows another embodiment and uses like reference numerals fromthe above figures where appropriate to facilitate clarity. Base member112b has a groove 126 providing a water passage directly receiving wateror receiving the water hose. Cap member 116b is mounted to base member112b by bolts 118b and 120b and has a fuel passage 128 for directlyreceiving the fuel or receiving the fuel line. Fuel passage 128 andwater passage 126 are spaced and separated by the material of cap 116b,and heat transfers therebetween through the cap material.

FIGS. 14 and 15 show another embodiment and use like reference numeralsfrom the above figures where appropriate to facilitate clarity. The sideof engine block 4 has a raised base member 130 integrally formedtherewith. Base member 130 has a serpentine S-shaped exposed groove 132therein for receiving water hose 40g. A cap member 134 is mounted bybolts such as 136 to base member 130 and has a fuel passage 138therethrough with threaded fittings 140 and 142 at its ends forconnection to fuel line 30g. Cap 134 has a plurality of fingerprojections such as 144 extending into groove 132 along differentportions of the serpentine path and deforming water hose 40g in ageneral C-shaped configuration, FIG. 15. Water hose 40g and fuel passage138 are spaced by the material of cap 134 for heat transfertherethrough, with increased surface contact area provided by fingers144.

FIG. 16 shows another embodiment and uses like reference numerals fromthe above figures where appropriate to facilitate clarity. A casthousing 146 is bolted to the engine block or fly wheel housing throughbolt or stud receiving apertures such as 148 and 150. Housing 146 has afuel passage 152 therethrough with threaded ends for attachment to thefuel line, and has a recessed exposed groove 154 for receiving waterhose 40h. A hose clamp 156 retains water hose 40h in groove 154 in heattransfer relation with the cast housing. Fuel passage 152 and water hose40h are in spaced relation separated by the cast housing materialtherebetween through which the heat is transferred.

FIG. 17 shows another embodiment and uses like reference numerals fromthe aboye figures where appropriate to facilitate clarity. A clamp isprovided by a clip 158 affixed, such as by braising, to fuel line 30iand retaining water hose 40i in snap-in relation and deforming waterhose 40i around fuel line 30i in a C-shaped configuration in crosssection. Two or more such clips 158 are provided. The clip has a centralportion 160 braised to fuel line 30i and extending into oppositelycurved portions 162 and 164 curving around and over the hose at 166 and168 and forming a pair of oppositely facing spring clip legs terminatingat facing edges 170 and 172 separated by a gap 174 throuqh which hose40i is inserted transversely to the axial direction of fuel line 30i.

FIGS. 18-20 show an alternative to the clamping arrangement of FIGS. 3and 4 and is preferred to facilitate ease of removal and replacement ofthe water hose. The fuel line cooler 34a includes water hose or conduit40a concentric to fuel line or conduit 30a and defining an annular space42a through which cooling water flows in direct contact with theexterior surface of fuel line 30a. Compression ring 46a around fuel line30a is compressed in sealing relation by compression nut 48a tightenedto threaded fitting 44a at threaded interface 47a. Fitting 44a is aroundfuel line 30a and has a smaller inner diameter portion 44b engaging fuelline 30a adjacent compression ring 46a and inward of threads 47a.Fitting 44a has a larger inner diameter portion 44c radially spacedoutwardly from fuel line 30a to define an annular gap coincident withannular space 42a. Portion 44c of fitting 44a has a port 202therethrough communicating with annular space 42a. Port 202 is anopening extending radially through fitting 44a relative to the axialextent of fuel line 30a. Hose 40a is disposed circumferentially aroundfitting 44a and has an aperture 204 aligned with opening 202. A clamp58a is disposed circumferentially around water hose 40a and clamps thehose to fitting 44a. Clamp 58a has mating serrated barbed fingers 60aand 62a, FIG. 20, between inner and outer fingers 59a and 64a. The clampis closed to a clamped condition by squeezing grip portions 63a and 65atowards each other. The clamp is released to an unclamped condition bypulling finger 64a outwardly to enable the separation of the serrationsof fingers 60a and 62a away from each other. The finger portions 59a-65aare like those in the above noted SNP 24 clamp known in the prior art.

Clamp 58a has an inner tubular portion 206 extending radially inwardlythrouqh aperture 204 in water hose 40a and through opening 202 infitting 44a to communicate with annular space 42a. Clamp 58a has anouter tubular portion 208 communicating with inner tubular portion 206along a common bore 210 therethrough. Tubular portion 208 has an outerbarbed configuration as at 212 for connection to water hose 36, FIG. 4,or other fluid carrying conduit. Fitting 44a has an exterior hexconfiguration for tightening to hex nut 48a, as in FIGS. 3 and 4, atthreaded interface 47a.

To facilitate removal and replacement of water hose 40a, one end of fuelline 30a is disconnected from the carburetor or from the fuel pump.Clamp 58a is then released, including withdrawal of inner tubularportion 206 out of opening 202 in fitting 44a and out of aperture 204 inwater hose 40a. This enables the water hose 40a to be axially slid offof fitting 44a. The inlet and outlet of water hose 40a have the sameclamping arrangements as such as 58a. Hence, in FIG. 18, if the left endof the fuel line is disconnected, water hose 40a is axially slidleftwardly such that the right end of the hose is slid off of the rightend fitting, and the entire water hose 40a slides leftwardly pastfitting 44a. The new replacement hose is then slide axially rightwardlyover fitting 44a and the right end of the new hose engages the rightfitting, and the left end of the new hose engages left fitting 44a. Inthe fitting and clamping arrangement in FIGS. 3 and 4, water hose 40cannot be axially moved because barbed port 54 is on the fitting, andhence water hose 40 cannot be axially slid therepast.

Clamp 58a has a pair of legs 214 and 216, FIG. 19, extending axiallyalong the outer surface of water hose 40a, and turned radially inwardlyat tabs 218 and 220, respectively, FIG. 20, engaging the left axial endof water hose 40a, to locate clamp 58a on the water hose and fitting,particularly providing alignment of inner tubular portion 206 withopening 202 in fitting 44a and with aperture 204 in water hose 40a.

It is recognized that various equivalents, alternatives andmodifications are possible within the scope of the appended claims.

We claim:
 1. In a marine propulsion system having a water cooled internal combustion engine in a heat-retentive compartment, and including a fuel line in said compartment supplying fuel to a carburetor for combustion by said engine, fuel line cooler means in said compartment in heat transfer relation with said fuel line and separate from and nonintegral with said fuel line, said fuel line cooler means having an inlet communicating with a source of cooling sea water to cool said fuel line and prevent vaporization of said fuel, including the prevention of fuel vaporization after turn-off of said engine by providing a thermally inertial mass in said compartment in heat transfer relation with said fuel to prevent vaporization of said fuel otherwise caused by heat from said engine after turn-off notwithstanding the lower fuel pressure and lower temperature of vaporization of fuel for the carburated said engine as compared to a high pressure fuel injected engine with higher temperatures of fuel vaporization, wherein said fuel line cooler means provides direct contact of said sea water with the exterior of an existing said fuel line.
 2. The invention according to claim 1 wherein said existing fuel line extends axially, and said fuel line cooler means comprises a water hose concentric to said existing fuel line and clamping means having a clamped condition sealing said water hose around said existing fuel line and having a released condition enabling said water hose to be axially slid off said fuel line, to facilitate installation and replacement of said water hose.
 3. In a marine propulsion system having an internal combustion engine in a heat-retentive compartment, and including a fuel line in said compartment supplying fuel for combustion by said engine, fuel line cooler means comprising means actively cooled during running of said engine, and upon turn-off of said engine providing a thermally inertial mass in said compartment in heat transfer relation with said fuel to prevent vaporization of said fuel otherwise caused by heat from said engine, wherein said fuel line cooler means has an inlet communicating with a source of cooling water for said engine and has an outlet for discharging water and comprising water pump means for pumping cooling water to said engine, wherein said inlet of said fuel line cooler means communicates with said water pump means such that said water pump means pumps cooling water both to said engine and to said fuel line cooler means, wherein said water pump means comprises a sea water pick-up pump for pumping sea water and an engine circulating pump for pumping water through said engine, wherein said inlet of said fuel line cooler means communicates with said sea water pick-up pump such that sea water is pumped through said fuel line cooler means and discharged at said outlet of said fuel line cooler means, and comprising a thermostat housing connected between said sea water pick-up pump and said engine circulating pump, and wherein said inlet of said fuel line cooler means is connected to said thermostat housing, such that the flow path of cooling sea water is from said sea water pick-up pump to said thermostat housing to said engine circulating pump, and such that the flow path of cooling sea water for said fuel line cooler means is from said thermostat housing to said inlet of said fuel line cooler means.
 4. In a marine propulsion system having an internal combustion engine in a heat-retentive compartment, and including a fuel line in said compartment supplying fuel for combustion by said engine, fuel line cooler means comprising means actively cooled during running of said engine, and upon turn-off of said engine providing a thermally inertial mass in said compartment in heat transfer relation with said fuel to prevent vaporization of said fuel otherwise caused by heat from said engine, wherein said fuel line cooler means has an inlet communicating with a source of cooling sea water for said engine and has an outlet for discharging water, wherein said engine has a fuel pump pumping fuel to a carburetor for supplying fuel for combustion, and wherein said fuel line cooler means is between said fuel pump and said carburetor and as close as possible to said fuel pump and cools the fuel line downstream of said fuel pump between said fuel pump and said carburetor.
 5. In a marine propulsion system having a water-cooled internal combustion engine in a heat-retentive compartment, and includinq a fuel line in said compartment supplying fuel for combustion by said engine, fuel line cooler means in said compartment in heat transfer relation with said fuel line and having an inlet communicating with a source of cooling water and having an outlet for discharging water, said fuel line cooler means comprising a water hose concentric to said fuel line and defining an annular space through which cooling water flows in direct contact with the exterior surface of said fuel line, at least one of said inlet and said outlet of said fuel line cooler means comprising a fitting around said fuel line having a port therethrough communicating with said annular space between said hose and said fuel line, said port comprising an opening extending radially through said fitting relative to the axial extent of said fuel line, said hose being disposed circumferentially around said fitting and having an aperture through said hose aligned with said opening in said fitting, and a clamp around said hose clamping said hose to said fitting, said clamp having an inner tubular portion extending radially inwardly through said aperture in said hose and through said opening in said fitting to communicate with said annular space between said hose and said fuel line, said clamp having an outer tubular portion extending radially outwardly for connection to another water hose.
 6. The invention according to claim 5 wherein said clamp is releaseable from said first mentioned hose including withdrawal of said inner tubular portion out of said opening in said fitting and out of said aperture in said first hose, such that said first hose may be slid axially away from said fitting, facilitating removal and replacement of said first hose.
 7. The invention according to claim 6 wherein said clamp has at least one leg extending axially along the outer surface of said first hose and having a tab extending radially inwardly from the end of the leg, which tab engages an axial end of said first hose to locate said clamp relative to said first hose and said fitting, including radial alignment of said inner tubular portion of said clamp with said aperture in said first hose and said opening in said fitting. 